Cura frustrations

Hey folks,
I’m getting a little exasperated here. I recently purchased a taz 6. Had reasonably good luck with the original single extruder, so decided to jump into the dual V3, fully expecting to have some failures due to being a noob - Lulzbot does advise a few months of single before getting into dual. And yep, I’ve run into many issues, such as having to reset the z axis regularly to avoid either scraping the bed or printing to thin air, lots of adhesion issues, lots of print quality issues, especially smearing between two colors or types of filament. I can accept that it takes some experience and experimentation to get those things dialed in, and have worked through some of them with trial and error and some Lulzbot support. Was hoping that at this price point things were a little more plug and play, but did fully expect a learning curve, and expect to have to learn more. A little frustrated, but not really all that worked up about these types of issues yet.

HOWEVER, two times in a row now, I’ve been partially through a large single material print and the extruder just stops; the extruder drive gear just stops moving, as if it’s not getting a signal. The carriage and bed keep moving normally, but the extrusion just stops at a random point. This is not a filament jam - I paused the print, and was able to manually (using fingers very slowly) to extrude just fine. Cables appear to be connect properly, Cura extrude button works. This is for about a 10 hour ABS print; 1st time it quit extruding at about the 2 hour point, 2nd time at about the 8 hour point. Arghh. This is lots of time and filament just thrown away. As far as what is there, the print quality seems to be okay - not great, but ok - probably just my own inexperience. For what it’s worth, I am using extruder 2 on the dual V3, with no 3d body assigned to extruder 1.** Filament is MatterHackers ABS, printing at 255.

Also, for some reason Cura keeps sinking the part -2 mm, reducing the overall height of my printed part. I change the z component to 0, then then it sinks back to -2mm when it slices. The part has some thin (.1 in) spots on the outer edges I’ve used to assist with adhesion in combination with the brim setting.

**I get how it would probably be better to switch back to the single extruder head, but nevertheless the extruder shouldn’t just quit.

The main reason I bought this machine was because of the combination of dual extrusion and large print volume. Right now, not so sure this was a good decision.

  1. has anybody else run into the extruder mechanism just stopping?
  2. any advise as far as what i need to check before i try again is appreciated.

Thanks all,

What version of CuraLE are you using? CuraLE 3.2 beta (with newer firmware) is working quite well for me on my TAZ 6 Dual Extruder V3. I have not experienced the problem(s) you are seeing.

I do, however, switch back and forth between my original single and the dual. I only use the dual when I need to use two filaments. I have successfully printed a project for my son that took 20 hours to print (and he wanted 6 of them in 6 different colors).

IMO, the single is much easier to clean when I switch filament types or colors. I can successfully do a cold extraction, shine a flashlight down from the top and see a spot of light on the bed!

I’m also quite fond of eSun’s Cleaning filament, or With a printing temperature of 160-280c it is wonderful for getting the filament path squeaky clean. It cold pulls at 110c giving an almost perfect impression of the inside of the nozzle and the rest of the path.

I am using 2.6.69.

And now for more fun - I put the single extruder back on, and get the following error:

Please Reset

According to the manual, this is likely due to a bad thermistor connection, but i am not sure what thermistor, or what to check, or how to reset.

Thanks all,


Just checked the resistances. Thermistor is 121 kohm, heater cartridge is 19.2 ohm

Got a reply from Lulzbot support, didn’t realize i needed to reflash to go back to a single extruder, seems to be working now.
'preciate the support. Wish the process was easier though.

When switching from Dual to Single, I flash the single firmware before I swap tool heads. Don’t forget to remove the Z min stop extension.

When switching from Single to Dual, I switch the tool head before I flash the dual firmware. Don’t forget to insert the Z min stop extension.

I have posted a tweak to the single extruder start gcode which uses as much of the triple wide wipe pad as possible.

"When switching from Dual to Single, I flash the single firmware before I swap tool heads. Don’t forget to remove the Z min stop extension. "

Why? To avoid the error? I flashed after the change, seemed to work OK.
Do you have to reset the z-offset? I seem to have to change that constantly to keep a good tight initial layer.

As long as the error message doesn’t bother you, re-flashing in any order works.

In newer LulzBot versions of Marlin, the E-steps and Z-offset are preset. LulzBot claims that E-steps does not need to be changed on the Dual V3, but the original single had an E-steps value printed on it and I change that when I swap tool heads (forgot about that one). You can also set the Z-offset if you find it necessary. Both E-steps and Z-offset can be saved to the EEPROM with an “M500” (and checked with an “M503”).

Since I’m using OctoPrint, I’ve added a plugin and some buttons to set both E-steps and Z-offset for each of my tool heads. You could also create some small Gcode files to put on your SD card that would do the same thing.

For my Dual V3, I’ve added “M218 T0 X0 Y0” and “M218 T1 X0 Y0” to the CuraLE start code and an “M218 T1 X13 Y0” to the end of my Simplify3D start code as S3D prefers that the firmware handle the nozzle offset. The M218 values are not stored in the EEPROM so they must be set for each printing session (or each print to be safe).